1. Field of the Invention
The present invention relates to a cloth presser provided with a thread end holder and a knife for cutting the end of the thread used at the beginning of a stitching operation.
2. Description of the Prior Art
An extension portion of thread available at the beginning of the stitching material to be sewn is useless and hinders the stitching operation with the progress of the stitching operation so that it is preferable to sever this portion by cutting it off the thread at the beginning of the stitching operation. For example, Japanese Utility Model Laid-Open Publication No. 62-109079 discloses means to cut the extension portion of thread while holding the end of the needle thread. That is, as shown in an exploded view of the prior art in FIG. 5 hereof, a cloth presser foot 3 is used. As shown in further detail in FIGS. 6 and 7 hereof, in this prior art a needle thread end guide groove 4 is cut into the cloth presser foot 3 and communicates with a needle location groove 3a at the side of a thread end holder 15. The cloth presser foot 3 has at the rear surface thereof a recess 5 to which a knife 6 is secured and has a screw hole 5a. The recess 5 crosses the thread end guide groove 4. The knife 6 has a hole 6a therethrough and is secured in the knife recess 5 in such a manner that a blade thereof crosses the thread guide groove 4 while a set screw 7 is inserted through hole 6a and screwed into hole 5a. The needle location 3a has a chamfer 8 at a base side thereof disposed under the cloth presser foot 3 and direction to the thread end guide groove 4 for guiding the thread. The needle location groove 3a has another chamfer 9 at an upper edge thereof at the side of the thread end holder 15. A member 10 is embedded in the knife fixing groove 5 in confronted relation with the knife 6 while crossing the thread end guide groove 4.
The cloth presser foot 3 is pivoted by a supporter and used as a cloth presser.
When the stitching operation is started, a needle thread B is held by the thread end holder 15 and forms an extension portion C between the thread end holder 15 and a first stitch D made in the sewn material E as shown in FIG. 6. With the prgress of the stitching operation, the first stitch D is guided by the chamfers 8, 9 to enter into the thread end guide groove 4 and contact the fixed knife 6 and is cut thereby.
However, at the time of cutting the extension thread C by the fixed knife 6 the stitching condition is changed such as the stitching speed is changed, causing the needle thread B to slide into the thread end guide groove 4 and be severed by the fixed knife. To prevent this undesired action, the needle thread B must not slide into the thread end guide groove 4.